You can stop and start it with CTRL-s and CTRL-q, respectively, and at the end of the run, you will get a list of any uninstalled packages.
"Debian GNU/Linux: Guide to Installation and Usage"
John Goerzen and Ossama Othman
Using CTRL-a followed by CTRL-k, you can delete the entire command line.
"Debian GNU/Linux: Guide to Installation and Usage"
John Goerzen and Ossama Othman
Press CTRL-z while you're reading to suspend the current foreground job and put the shell in the foreground.
"Debian GNU/Linux: Guide to Installation and Usage"
John Goerzen and Ossama Othman